Contact information is available on PyPI.
The following are not considered vulnerabilities in pathspec:
ReDoS / regular expression complexity: pathspec is a pattern-matching library, not a sandboxed input parser. The regex complexity is proportional to that of the pattern. Applications that expose pattern input to untrusted users are responsible for sanitizing that input.
Any actual vulnerabilities discovered in Python's re module, hyperscan, or google-re2 should be reported to the maintainers of those libraries.